9-cis retinoic acid improves developmental competence and embryo quality during in vitro maturation of bovine oocytes through the inhibition of oocyte tumor necrosis factor-α gene expression

J Anim Sci. 2011 Sep;89(9):2759-67. doi: 10.2527/jas.2011-3848. Epub 2011 Apr 8.

Abstract

Retinoic acid (RA; all-trans RA and 9-cis RA) enhances embryo developmental competence and quality through multiple mechanisms affecting the oocyte and preimplantation embryo. Folliculogenesis and oocyte maturation are influenced by tumor necrosis factor-α (TNF-α) via inhibition of aromatase activity and estradiol secretion in granulosa cells. Retinoic acid inhibits TNF-α production in various cell lines. The aim of the present study was to determine whether oocyte TNF-α concentrations regulate developmental competence and embryo quality and if the beneficial effects of 9-cis RA are mediated through attenuation of oocyte TNF-α production. Bovine cumulus oocyte complexes collected from abattoir ovaries were matured in maturation medium in the absence (control) or presence of 5 nM 9-cis RA (RA), 100 ng/mL of recombinant bovine TNF-α (TNF), or 5 nM 9-cis RA + 100 ng/mL of recombinant bovine TNF-α (RA+TNF). Oocytes were subsequently collected for gene expression analysis or subjected to in vitro fertilization and culture. Apoptosis and gene expression were analyzed in d-8 blastocysts. Results indicated that 9-cis RA downregulated (P < 0.01) both basal and TNF-α-induced TNF-α mRNA in oocytes (1.0-fold in control, 0.4-fold in RA, 2.1-fold in TNF, and 0.7-fold in RA+TNF). The 9-cis RA increased (P < 0.001) blastocyst development rates (37.1 ± 6.9 vs. 23.6 ± 8.0%) and total cell number (138.4 ± 19.2 vs. 120.2 ± 24.5) and reduced (P < 0.001) the percentage of apoptotic cells (3.3 ± 2.0 vs. 5.6 ± 2.3%) compared with controls. Expression of caspase 3 (0.4- vs. 1.0-fold) and TNF-α (0.4- vs. 1.0-fold) mRNA was downregulated (P < 0.05) in RA-treated blastocysts compared with controls. Moreover, 9-cis RA rescued (P < 0.001) development rates (24.5 ± 11.1 vs. 15.6 ± 9.0%), increased total cell number (124.6 ± 36.5 vs. 106.9 ± 31.1), and reduced apoptosis (5.8 ± 2.0 vs. 8.1 ± 3.1%) in blastocysts exposed to TNF-α (TNF group). Caspase 3 (0.8-fold in RA+TNF vs. 2.2-fold in TNF) and TNF-α (0.3-fold in RA+TNF vs. 2.8-fold in TNF) mRNA expression was attenuated (P < 0.05) in TNF-α-treated blastocysts. In conclusion, the present study suggests that 9-cis RA exerts its beneficial roles on oocyte developmental competence and embryo quality by attenuating oocyte TNF-α mRNA expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alitretinoin
  • Animals
  • Blastocyst / drug effects
  • Blastocyst / metabolism
  • Caspase 3 / drug effects
  • Cattle
  • Embryo, Mammalian / drug effects*
  • Embryonic Development / drug effects*
  • Female
  • Gene Expression / drug effects
  • In Situ Nick-End Labeling / veterinary
  • In Vitro Techniques
  • Oocytes / drug effects*
  • Oocytes / growth & development
  • Oocytes / metabolism
  • Real-Time Polymerase Chain Reaction / veterinary
  • Tretinoin / pharmacology*
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*
  • Tumor Necrosis Factor-alpha / biosynthesis
  • Tumor Necrosis Factor-alpha / physiology

Substances

  • Tumor Necrosis Factor-alpha
  • Alitretinoin
  • Tretinoin
  • Caspase 3